Work-table height adjusting means for blind-stitch sewing machines



Apnl 8, 1958 F. PARRY 2,829,613

WORK-TABLE HEIGHT ADJUSTING MEANS FOR BLIND-STITCH SEWING MACHINES Filed Oct. 19, 1954 2 Sheets-Sheet 1 IN V EN TOR.

Frank Parry BY WITNESS wa bz QM A TTORIVE Y April 8, 1958 F. PARRY 2,829,613

WORK-TABLE HEIGHT ADJUSTING MEANS FOR BLIND-STITCH SEWING MACHINES Filed Oct. 19, 1954 2 Sheets-Sheet 2 2 I 1/ p. Q l \\R 7' X W j r 5 isms as Wfi\ INVENTOR.

a Frank Parry n a B? WITNESS ATTORNEY United States Patent WORK-TABLE HEIGHT ADJUSTING MEANS FOR BLIND-STITCH SEWING MACHINES Frank Parry, Trumbull, Conn., assignor to The Singer Manufacturing Company, Elizabeth, N. J., a corporation .of New Jersey Application October 19, 1954, Serial No. 463,089

3 Claims. (Cl. 112--260) The present invention relates to blind-stitch sewing 2,829,613 Patented Apr. 8, 1958 with depending walls 13 in which is secured a pivot shaft machines and has for a primary object to provide an improved work-table height adjusting means for blindstitch sewing machines. Specifically, it is an object of this invention to provide such a work-table height adjusting means of simplified construction and, therefore, economical, and yet durable, dependable and efiicient in operation.

Having in mind the above and other objects that will be evident from an understanding of this disclosure, the invention comprises the devices, combinations and arrangements of parts as illustrated in the presently preferred embodiment of the invention which is hereinafter set forth in such detail as to enable those skilled in the art readily to understand the function, operation, construction and advantages of it when read in conjunction with the accompanying drawings in which:

Fig. 1 is a top plan view of a machine constructed in accordance with the present invention, the bed coverplate being removed and certain of the parts being in section to illustrate the details of the machine.

Fig. 2 is a vertical sectional view of the machine taken substantially on the line 2-2 of Fig. l with some parts broken away.

The present invention is illustrated in the drawings as embodied in a singie-thread chain-stitch blind-stitch sewing machine of the type as disclosed, for example, in the U. S. patent of Parry, No. 2,678,619. The machine is herein illustrated and described only insofar as is necessary to obtain a full understandingof the present invention and it is to be understood that the various other details of the machine may be of any suitable construction.

The illustrated machine comprises a frame having a base 1 and a standard 2 rising from the right rear corner thereof and carrying the usual laterally extending horizontal arm 3 and forwardly extending frame-arm 4. The arm 4 in turn carries the stitch-forming mechanism including the arcuately moving curved needle 5 and looper 6 and the four-motion feed-dog 7 and resser-plate 8. There is provided a work-table 9 having a tubular worksupporting free end 10 which underlies the free end of the arm 4 and having a substantially rectangular base portion 11.

In the usual manner the work-table 9 is designed to be urged upwardly toward the frame 4 into a stop-position in which it is spaced from the presser-plate 8 a distance that is determined by a stop regulated in accordance with the thickness of the work, the work being urged into engagement with the presser-plate 8 by the resilientlybiased vertically yieldable work-clamping members 12 carried by the work-table. The work-table is thus supported so that it may be depressed for the introduction or work and when released will rise to its normal elevated or Working position. This working position is made adjustable to provide for adjustment of the spacing of the work-table and the ridge-former carried thereby relative to the presser-plate in order to regulate the depth of penetration of the work by the curved needle.

14 arranged parallel to and forwardly of the longitudinal axis of the work-table and transversely of the longitudinal axis of the base 1. The shaft 14 is journaled in upstanding ears 15 of a bracket 16 that is secured to the forward end of the base 1 as by screws 17. The work-table 9 is thereby adapted to be pivoted about the pivot-shaft 14 and the work-supporting tubuiar portion 10 is adapted to be moved vertically toward and away from the framearm 4.

The work-table 9 is resiliently urged about the pivot shaft 14 in a direction toward its normal elevated position by a spring 18 that is arranged longitudinally of the base 1. The spring 13 is adjustably secured to the rear end of the base 1 by a bolt 19 extending through a bore in the base and cooperating with a nut 20'. At its forward end, the spring 18 is connected to the apron 21 of the work-table by means of an anchor pin 22 threaded through a bore 23 in the apron and having a reduced end portion 24 extending through a vertical slot 25 in the apron. The hook-shaped end of the spring 18 extends into the slot 25 in the apron and receives the end portion 24 of the pin 22 to secure the end of the spring to the apron.

The adjustable stop means for limiting the pivotal movement of the work-table under the action of the spring 18 comprises a bell-crank lever 26 having a stoparm 27 that abuts at its free end against the inner surface of the apron 21 at a point below the axis of the pivot-shaft 14. The bell-crank lever 26 also includes a pivot-arm 28 and a lever-arm 29. The pivot arm 28 is provided with a strap portion 30 that loosely embraces the pivot-shaft 14, whereby the bell-crank lever 26 is freely pivoted to the pivot-shaft. The lever 29 extends rearwardly through the base 1 and then upwardly into the standard 2 to define a vertical end portion 31. Adjacent the end thereof, the portion 31 has formed therein an open-ended horizontal slot 32 that receives a horizontal pin 33 carried at the lower end of a vertical slide-rod 34. The pin 33 preferably comprises a screw threaded through the slide-rod 34 and having a cylindrical reduced end that extends into the slot 32. The slide-rod 34 is mounted vertically for reciprocation in the standard 2. in a suitable bushing 35, and at its upper end the sliderod is provided with a reduced and threaded portion 36. Cooperating with the portion 36 is a not indicated generally at 37 and comprising an internally threaded sleeve 38 that receives the portion 36 and a hand-grasp 39 that is secured to the exposed end of the sleeve 33 at the top of the standard by a screw 40 threaded into a reduced diameter extension 41 of the sleeve to clamp the hand-grasp 39 between the head of the screw and the shoulder at the reduced portion. The sleeve 38 is held against vertical axial movement by a set-screw 42 having a smooth cylindrical end that extends into an annular groove 43 in the periphery of the sleeve 38.

The operation of the improved blind-stitch machine work-table height adjusting means as above disclosed is believed to be obvious from an understanding of the mechanism. When the hand-grasp 39 is manually rotated, the sleeve 38 will be rotated and through cooperation of the sleeve with the threaded portion 36' of the sliderod 34, rotation of the sleeve will eifect axial movement of the slide-rod. The lower end of the slide'rod 34 is connected to the end of the lever-arm 29 of the bell-crank lever 26 and, therefore, axial movement of the siiderod will cause pivotal movement of the bell-crank about the pivot-shaft 14 which in turn will vary the position of the stop-arm 27 and thereby efi'ect an adjustment of the stop or normal raised position of the work-table 9.

Numerous alterations of the structure herein disclosed 3 will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to a preferred embodiment of my invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.

Having thus described the nature of the invention, what I claim herein is:

1. A work-table height adjusting means for a blindstitch sewing machine having a frame, a stationary presser-plate carried by said frame and a work-table pivotally mounted on said frame for turning movement about a pivot-axis and arranged in opposition to said presserplate, means for biasing said work-table about the pivotaxis thereof toward said presser-plate, and adjustable stop-means for limiting the pivotal movement of said work-table under the action of said biasing means, said stop-means comprising a bell-crank lever mounted in said frame for pivotal movement, said bell-crank lever having a stop-arm integral therewith and extending to engage directly said work table to form an abutment therefor to limit the pivotal movement thereof and a lever-arm extending through said frame, and manually operable means operatively connected to said lever-arm and having a portion extending to the exterior of said frame for actuating said lever-arm to pivot said bellcrank lever about the pivot axis thereof and thereby effect an adjustment of the position of said stoparm.

2. A work-table height adjusting means for a blindstitch sewing machine having a frame, a stationary resser-plate carried by said frame and a work-table pivotally mounted on said frame for turning movement about a pivot axis and arranged in opposition to said resser-plate, means for biasing said work-table about the pivot-axis thereof toward said resser-plate, and adjustable stop-means for limiting the pivotal movement of said work-table under the action of said biasing means, said stop-means comprising a bell-crank lever loosely mounted on said pivot-axis for pivotal movement relative thereto, said bell-crank lever having a stop-arm arranged to form an abutment for said work-table to limit the pivotal movement thereof and a lever-arm extending through .4 said frame, a slide-rod mounted in said frame for axial sliding movement and operatively connected to said leverarm for actuating the same to pivot the bell-crank lever about said pivot-axis upon axial sliding movements of said slide-rod and thereby effect an adjustment of the position of said stop-arm, and a nut carried for rotation by said frame and having a hand-grasp disposed on the exterior of said frame, said nut having a threaded connection with said slide-rod for imparting axial sliding movement to said slide-rod upon rotation of said nut.

3. A work-table height adjusting means for a blindstitch sewing machine having a frame including a base and a standard rising from one end of said base and carrying a stationary resser-plate, a. work-table pivoted to said base at the other end thereof on a horizontal pivotaxis arranged generally transverse to said base, resilient means for biasing said work-table about the pivot-axis thereof toward said presser-plate into an elevated position, and adjustable stop-means for limiting the pivotal movement of said work-table under the action of said resilient means, said stop-means comprising a bell-crank lever loosely mounted on said pivot-axis for pivotal movement relative thereto, said bell-crank lever having a stop-arm arranged to form an abutment for said worktable to limit the pivotal movement thereof, and a leverarm extending longitudinally through said base and into said standard, a slide-rod mounted vertically in said standard for axial sliding movement and operatively connected to said lever-arm for oscillating said bellcrank lever about the pivot-axis thereof upon reciprocation of said sliderod to efiect an adjustment of the position of said stoparm, and a nut arranged axially of said slide-rod and carried for rotation by said standard, said nut extending into said standard at a point remote from said base and having a hand-grasp disposed on the exterior of said standard, said nut having a threaded connection with said slide-rod for imparting axial sliding movement to said slide-rod upon rotation of said nut.

References Cited in the file of this patent UNITED STATES PATENTS 

